﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace Elight.Utility.Security
{
    public class AESHelper
    {
        public static string AES_decrypt(string encryptedDataStr, string key, string iv)
        {
            RijndaelManaged rijalg = new RijndaelManaged();
            //-----------------    
            //设置 cipher 格式 AES-128-CBC    
            rijalg.KeySize = 128;
            rijalg.Padding = PaddingMode.PKCS7;
            rijalg.Mode = CipherMode.CBC;
            rijalg.Key = Convert.FromBase64String(key);
            rijalg.IV = Convert.FromBase64String(iv);
            byte[] encryptedData = Convert.FromBase64String(encryptedDataStr);
            //解密    
            ICryptoTransform decryptor = rijalg.CreateDecryptor(rijalg.Key, rijalg.IV);
            string result;
            using (MemoryStream msDecrypt = new MemoryStream(encryptedData))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        result = srDecrypt.ReadToEnd();
                    }
                }
            }
            return result;
        }
    }
}
